Safety-stop for elevators.



J. HOPPER.

SAFETY STOP FOR ELEVATORS.

APPLICATION nun-r2340, 1911.

Patented Oct. 17, 1911.

. 1 n 2 a m m m v 0 N W. 1 u 1 a F 4 /5 m 1 A r 2 z W v 4 Y M M r \MITNESSESI in atBaxter, in the county of vator's,.of which improvements thefollowlend itself to serious ,JOHN HOPPER, 0F BAXTEB, VIEST VIRGINIA.

v SAFETY-STOP FOR 'ELEVATQRS.

Specification of Letters Patent. Application filed February '10, 1911.Serial No. 607,799.

To all whom {it may concern:

to like parts.

Be" it known that I, JOHN Horrnn, resid- Marion and b The elevator carshown herein conven- State of West Virginia, a subject of the ientlyconsists of two major parts, a plat- Emperor of Austria-Hungary, haveinform and a frame, which parts move simulvented or discovered certainnew and usetaneously in the normal operation of the ful Improvements inSafety-Stops for Elecar, but are movable with reference to each other incase an accident causes the cable to slacken. Of these parts, theplatform 1 is conveniently provided with sides 2. Vertical sustainingmembers 3, 3 are secure to each side, and, at their upper ends, the saidsustaining members are yoked together by a suitable block a, which maybe suspended from the cable 5 by a bolt 6. block 4 is inclosed looselyWithin the upper portion of the frame, which upper portion convenientlyconsists of a horizontal channel 7 and vertical plates 8. To the saidplates 8 I secure guide blocks, suitable in form and in construction, tothe particular type of guideposts used. As usually constructed theguide-posts 9 are made of wood and are rectangular in cross-section. Theguideblocks for such guide-posts I preferably make of pairs of angles 10and 10, suitably secured to the vertical plates 8, as by lug angles 11,and I arrange the blocks one on each side of a guide post. To each angle10 I suit-ably secure an adjusting-bar 12, to the end that, as the guideblocks wear away, not only the loose play may be taken up, but also aslight frictional contact may be maintained. Preferably, the saidadjusting-bars 12 are made of steel flats, suitably provided with smoothholes, which extend partly through'the flats, and into which thescrew-threaded bolts 13 extend. It will be understood that the angles 10have screw-threaded holes, which register with the smooth holes of theadjusting-bars, and that a turning of thebolts 13 may be effective tomove the adjusting-bars away from the angles 10, thereby diminishing thewidth of the passageways for the guideposts.

The pair of guide blocks 10 and 10 may be connected to each other attheir lower ends, as by plates 14:, suitably provided with bearings forthe rotatable shafts 15 and 15, on which shafts I secure indentedcamshaped blocks 16, preferably placing one on each. end of each shaft.The shafts are suiting is a specification.

Elevator-cars that are used primarily for handling articles of commerce,for example such as operate in mining shafts, usually consist of aplatform, either rigidly or movably sustained within a frame, whichframe is guided by vertical posts in the movement up and down the shaft.To the end that the car may not fall, in case the cable breaks when thecar is in elevated position, the car has been provided with suitablecam-shaped blocks, with indented surfaces, to engage the guide-posts assoon as the cable becomes slack,'due to its rupture or any other cause.As heretofore constructed, cam-blocks of the character described havebeen operated by springs. In the operation of such elevators, theguide-posts, which are usually made of Wood, become worn, and therebyconsiderable play is allowed between the posts and the guide-blocks ofthe frame of the car, which play is of itself undesirable in the normaloperation of the elevator and may consequences by permitting thecam-blocks to turn over completely in case the cable should break.

My invention relates to improvements in elevators of the characterdescribed and the object of my invention is to provide a compensationfor the wearing of the guide-post and in so doing to wprovide a safetydevice for elevator cars that willnot be dependent upon the uncertainaction of a spring.

While my invention finds application in any elevator wherein the aboveconditions arise I choose to describe it in its application to anelevator of the type usually used in a mine shaft.

In the accompanying drawing, which forms part of this specification,Figure 1 is an elevation of a freight elevator embodying my invention;Fig. 2 is a side view 0 the same; and Fig. 3 is a sectional view takenon the line III-III, Fig. 2.

the several figures like numerals refer The said Patented oer. 17,1911.

ably connected, as by levers and links, to the. platform, to the endthat, when the elevator is running normally, the indented cams 16 willbe held away from engagement with the guide-posts, but that, 'when theplatform has moved downward a little in advance of the frame (as itwill, should the rope 5 break) the said cams will be brought intoengagement with the guide-posts, and will thereby stop the cars descent,in a manner that is well known by those skilled in the art. 7

That the plat-form will drop in advance of the frame, in case the cableshould break or slacken, will be understood from the fact that theguide-blocks are adjusted to constantly have a frictional engagementwith the guide-posts, which frictional engagement will retard thedescent of the frame sufficiently to allow the platform to fall inadvance of the frame and thereby bring the car to a stand-still asheretofore explained. It will be observed of my invention that a safetystop is accomplished without employing a spring, the reliability ofwhich has been found by experience to be uncertain. Furthermore, it willbe understood that the operation of one of the shafts 15 or 15 with itscam-block 16, will be suflicient'to stop the car, and it will beobserved that the shaft l5 with the cams 16, being arranged to engagethe posts 9 on the sides opposite the ad'- justing-bars 12, will remain,whatever he the degree of adjustment, in fixed relative position to thesaid guide-posts, so that it will be impossible for the said cams toturn completely over in consequence of the wearing away of the substanceof the posts, and thereby permit the car to drop, an occurrence thatwould remain possible in case the adjustment were taken up equally oneach side of the posts or in case the adjustments were not taken up atall.

I do not wish to limit myself to the details of construction shown anddescribed morass? herein, for obviously-many changes may be made bythose skilled in the artwithout departing from the spirit of myinvention.

I claim as my invention:

1. In an elevator, the combination of guide posts and a car, said carconsisting of a frame and a platform, which members move in unison inthe normal operation of the car, but which may move relatively to eachother when the car is unsupported, a

safety-cam rotatably secured to one of said car-members and havingoperative connection to the other of said car-members, an adjusting barsecured to the safety-camcarrying car-member and maintaining constantfriction with the elevator guides during the operation of the car, saidbar being operative (in case the car-supporting meniber gives away) toretard the downward movement of the safety-cam-carrying earmemberrelative to the said other car-memher, said relative downward movementsof the car members being operative to set the said safety cams,substantially as described.

2. In an elevator, the combination of guide-posts and a car, said carcomprising asuspended platform and a frame movably sustained by saidplatform, said frame pro vided with adjustable passageways main tainingconstant friction with said guideposts, a shaft rotatably secured tosaid frame and provided with a safety-cam,

an arm rigidly secured to said shaft and having linked connection tosaid platform, said friction passageways being operative l to retard thedownward movement of the I frame to accomplish a setting of thesafetycams 111 case of accident to the car-supporting member,substantially as described.

In testimony whereof I have hereunto set my hand.

JOHN HOFFER. Witnesses F. Monorrnr, E. WV. GRIFFITH.

